1. Field of the Invention
The present invention relates to guidance systems for remote work vehicles. More specifically, it relates to a method of controlling a remote work vehicle by a timed pulse broadcast to, and then returned by, a stationary antenna/transponder placed at the periphery of the worksite. It should be understood from the outset that the term "remote work vehicles" is not necessarily limited to land traversing vehicles or to vehicles used exclusively for work, and the term "vehicles" is not necessarily limited to wheeled vehicles.
The potential fields of use for this invention range from a simple lawn mower as shown herein, to controlling vehicles for cleaning up toxic waste sites, to interplanetary space or undersea exploration. Other applications for the invention could be on a vacuuming machine, snow thrower, leaf blower, fertilizer spreader, floor waxer, or power screed. Thus it can be seen that the potential fields of use for this invention are myriad and the particular preferred embodiment described herein is in no way meant to limit the use of the invention to the particular field chosen for exposition of the details of the invention.
A comprehensive listing of all the possible fields to which this invention may be applied is limited only by the imagination and is therefore not provided herein. Some of the more obvious applications are mentioned herein in the interest of providing a full and complete disclosure of the unique properties of this previously unknown general purpose article of manufacture. It is to be understood from the outset that the scope of this invention is not limited to these fields or to the specific examples of potential uses presented hereinafter.
2. Description of the Prior Art
In many instances, for safety or efficiency reasons, it is desirable for the working vehicle to be controlled from a remote site. This does not always entail cameras and servos. In a number of environments, the operator of the vehicle is in visual contact with the unit.
Robotic devices for mowing expansive areas are old and well known in the art. Many such devices attempt to operate in a totally automatic fashion without a human in the loop. When such a device encounters an unexpected obstacle or condition disaster usually results. This invention is primarily concerned with providing semi-automatic or operator intervened control. However, the technology developed herein can certainly find application in fully automatic control systems.
The following known prior art has been directed to providing robotic mowing devices. In a search conducted in this field, the following patents were uncovered that relate to the present invention. As will be seen, the simplicity and effectiveness of my invention is not rivaled in the prior art.
U.S. Pat. No. 5,083,629, issued on Jan. 28, 1992, to Chih-Li Chang there is disclosed a walking control mechanism for automatically controlled vehicles. The device senses through a feedback odometer the distance travelled, and at a predetermined point turns on the separately controlled drive wheels to move back and forth across the work area.
U.S. Pat. No. 4,994,970, issued on Feb. 28, 1991, to Akio Noji et al. discloses a working robot that, through a light beam detector, determines its position within a set working area as it proceeds; and when the accumulator is full, through this position detector means is able to navigate its way to a drop off point. By contrast, the device of the instant invention does not use a light beam detector.
Another patent of interest is U.S. Pat. No. 4,944,140, issued to Richard L. Donaghey on Jul. 31, 1990. This discloses a cable guidance system for a self-propelled machine. By contrast the device of the instant invention does not depend in any way on cable guidance.
Lastly, U.S. Pat. No. 4,694,639, issued to Sheng K. Chen et al. on Sep. 27, 1987, there is disclosed a robotic lawn mower that incorporates a paper tape recorder and an optical reader that allows the device, after once being guided through or over a course or yard, to repeat the path without further need for human guidance. By contrast, the device of the instant invention does not depend on the recording of a learning session.
It will be noted that none the prior art devices utilize a human operating a joystick as in the instant invention. Also the specific guidance method of steering by driving is not shown by the prior art.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.